| Until recently, haloalkane dehalogenases have only been isolated from bacteria living in contaminated environments. Jesenska et al. (2000) has shown that also mycobacteria isolated from human and animal tissues and from uncontaminated sources can dehalogenate haloalkanes by a hydrolytic mechanism. Haloalkane dehalogenase gene dhmA from bacterium Mycobacterium avium N85 has been cloned and its expression product biochemically characterized. Furthermore, many new sequences of putative haloalkane dehalogenases were identified in the bacteria with genomes, for example Mycobacterium tuberculosis, Mycobacterium avium, Mycobacterium paratuberculosis, Mesorhizobium loti, Xylella fastidiosa, Photobacterium profundum and Caulobacter crescentus Intra- and inter-species distribution of haloalkane dehalogenase genes will be studied using PCR technique. Selected genes will be sequenced to obtain a data for phylogenetic analysis, cloned and expressed to provide a material for mechanistic studies and construction of novel biocatalysts. Haloalkane dehalogenase-specific probes will be designed and experimentally validated. These probes can serve in the bioremediation projects for the screening of dehalogenating bacteria in a subsurface. |
